Thanks for the link dsfloyd. Great write up there. I want to do this with my 2007 Silverado Classic. It seems like the same set up, but then there is this "IMPORTANT NOTE: This will NOT work for 2002 or 2007+ models..." I will have to dig around the fuse box and check it out tomorrow. Anyone know why this may not work in the 02 & 07 models? I know this is for an Avalanche, but it seems to be the same set up as my silverado. If anyone knows more about this please fill me in because I would like to do the all on hi. Or at least do the fogs on with the high beams. I do overnight trips to Michigan a couple times a year so they would be nice on the quiet highways and back roads. Thanks

Did this mod tonight. Everything was the exact same on my 07 classic. Works good and it was an easy install. Took about 20 minutes with me going extra slow and double checking everything. Getting the relays back in was a squeeze but that was about the hardest part. I'm not too sure if I am going to keep the Full DTRL, but I love the All On Hi already...

I've been irritated by having to manually turn my fog lamps on each time I start the truck at night and the instructions provided here allowed me to ascertain how to have fog lamps automatically come on with low beams ... as well as have my low beams remain on when my high beams are engaged. The entire process from start to finish took me less than 10 minutes (including testing). I didn't bother with DRL's because they're not bright enough to be relevant in my equation...

I agree this should be stickied, because anyone who can read and follow directions can get this done ... and someone with half a brain can pick/choose which portions of it are relevant to him/her and do only those pieces. The link provided by dsfloyd provides instructions on what to get (specific diodes), how to prepare them (heat shrink and trim them), and perfect step-by-step instructions on how to install them.